Tagline mechanism



March 1952 P. A. OR'TON, SR 2,588,037

TAGLINE MECHANISM Filed Sept. 30, 1950 2 SHEETS-SHEET l March 4, 1952 P.A. ORTON, SR 2,588,037

TAGLINE MECHANISM Filed Sept. 30, 1950 2 SHEETSSHEET 2 I Cl: mer P-92 a5 4 50am 6% 30love 50mm? z'zpekz/ak Pz/d Ear/011,52.

Patented Mar. 4, 1952 UNITED STATES PATENT OFFICE Application September30, 1950', serial No. 187;721'

12 Claims.

This invention relates to a tagline tensioning device and moreparticularly to a tagline device actuated by compressed air and equippedwith means for rapidly damping out oscillations which may exist in thetagline tensioning device.

A tagline, as applied to a lifting crane, for example, is a device forsteadying the load suspended from the crane to prevent the load fromrotating when hanging on the hoisting lines. The tagline also serves tostop the tendency of the load or crane bucket to swing in or out. If theload of a crane is permitted to rotate, the oper ating cables willbecome twisted and proper control of the load is hindered. The taglineis applied primarily to clam shell and other such types of buckets,grapples, electromagnets, etc., although it is also used forsteadying aload such as a structural steel member.

The principle of the tagline is that, by maintaining a tension in thetagline, the load suspended from the crane boom is steadied and rotationabout a vertical axis is hindered. It is important that the tension inthe tagline be maintained substantially constant while the load ishoisted or lowered.

A number of difierent devices have been developed for maintaining a,tension upon the tagline. The simplest device consists of a counterweight traveling on guides mounted either in the boom itself or in thevertical guides on the revolving superstructure of the crane.

Another commondevice consists of nothing more orless than drum on whichthe tagline is wound and upon which a tension is maintained by means ofa spiral spring, similar to a clock spring, or several such springs inseries.

The objections to the counterweight type ofdevices are that if therunway is mounted in the boom, the pull of the counterweight will varywith the boom angle. If the runway is'mounted on the superstructure,space is then occupied that could well be devoted to other purposes and,in addition, the mechanism becomes rather'complicated.

The spring operated tagline devices-are expen sive and provide a tensionon the tagline which varies widely depending upon the position of theload to be steadied.

A further objection to both of these devices mentioned is thatnone ofthem are rapidly selfdamping; that is, a material amount of the energyof the moving load suspended from the boom is not quickly absorbed bythe tagline tensioning device. Unless the tagline is rapidly selfdamping, there is a tendency for the load to oscillate. It is thennecessary to await damping of these 2 manipulated. Therefore, it isdesirable" that a large amount of the energy of the-moving load beabsorbed by the tagline tensioning device as short a time as possible,for thenthe moving oscillations before the load can be accurately loadis brought to rest more rapidly andcontrol of the load is more easilyobtained.

Thus, one of the objects of this invention is to provide a novel taglinetensioning device which-is mounted on the boomof a crane or the like-andwhich device maintains substantially a constant tension in the taglineregardlessof the position of the crane boom.

Another object of this invention is to provide a tagline tensionindevice wherein the oscillations which may exist in the tagline devicearerapidly damped out. I

A" further object of this invention is: to provide a novel taglinetensioning device wherein. the tension in the tagline is regulated bycompressed air pressure and wherein the tensionintli tagline may beeasily regulated.

Still another object-of this inventionisto-provide atagline tensioningdevice for crane buckets wherein a relatively large movement ofthe-crane bucket is accommodatedbya" relatively small movement in thetagline tensioning device.

Still a further object of this invention isto provide a taglinetensioning device-for a crane or the like, which device isr'elativelycompact and which may be simply and inexpensively mounted on thecranesboom.

And still another object of thisinvention'is to provide afluid pressuresystem for? a fluid pres-- sure operated tagline tensioning device;which fluid pressure system is adapted to? absorb; or supply the fluidwhich operates the tagline ten si'oningdevice without any appreciablevariation in thefluid pressure operating the tagline device.

And still a further object of this inventionis to provide afluidpressure system for use: with'a pressurized cylinder of a taglinetensioning. device, which fluid pressure system is; adapted. to receivethefiuid pushed from the cylinder,.when2a sudden force is applied to thetaglinawithout havingan appreciable rise in the pressure within saidcylinder;

Further obj sets and advantages of; this invexL tion will becomeapparent. as the. following description proceeds and the features ofnovelty which characterize this invention will-be pointed out withparticularity in the: claimsannexed to and forming part of thisspecification.

A preferred embodiment of the: invention is shown inth'e accompanying;drawing in which Figure" 1' is an illustration ofa-crane withimy noveltagline tensioning device" installed on the boom of said crane;

Figure 2 is an enlarged isometric view of a portion of the boom of thecrane showing my tagline tensioning device;

Figure 3 is a view of portions of the tagline tensioning device, takenon the line 33 of Figure 2;

Figure 4 is a cross-sectional view of the portion of the taglinetensioning device shown in Figure 3 and is taken on the line 4-4 ofFigure 3;

Figure 5 is a cross-sectional view taken on the line 55 of Figure 3;

Figure 6 is a diagrammatic illustration of one piping system forsupplying compressed air to the cylinder of the tagline tensioningdevice;

Figure 7 is a diagrammatic illustration of a second piping system forsupplying compressed air to the cylinder of the tagline tensioningdevice; and

Figure 8 is a diagrammatic illustration of a third piping system forsupplying compressed air to the cylinder of the tagline tensioningdevice.

Referring now to the drawings, there is shown in Figure 1 a cranegenerally indicated at IU consisting of a deck l2 mounted on wheels l4and having a cab I6 and a crane boom l8 mounted thereupon. Suspendedfrom the extended end of the crane boom l8 by means of hoisting wires 20is a crane bucket generally indicated at 22. A tagline 24 is attached atone end to the crane bucket 22 and is actuated by my tagline tensioningmechanism, generally indicated at 26.

Referring now to Figure 2, the tagline tensioning device 26 is shown asconsisting of a cylinder 28 and a piston 30 which is mounted within thecylinder 28. Pressure is applied to one face of the piston by means of apressurized compressible fluid such as air. Secured to piston 30 bymeans of piston rod 32 are a pair of sheaves 34 over which are wound afirst cable 36. This first cable 36 is secured at one end 38, and theother end of first cable 36 is wound around a first drum 40.

The first drum 40 is secured to a rotatably mounted shaft 42 which has asecond drum 44 also mounted thereon. The shaft 42 is rotatablyjournalled in structural member 46 of crane boom l8. One end of thetagline 24 is wound around the second drum 44 and the other end oftagline 24 is connected to the crane bucket 22.

Referring more particularly to the air cylinder as shown in Figures 3and 4, said air cylinder 28 is mounted by means of support members 48and 50 upon a plate portion 52 of crane boom I8. Support member 48 has acylindrical cap portion 49 which closes one end of the cylinder 28 andserves as the head of the cylinder 28. The support member 50 has acylindrical plug portion 5| which closes the other end of a cylinder 28.Support members 48 and 58 are secured to plate 52 by means of bolts 41.

Compressed air is introduced into one end of cylinder 28 by means of acompressed air hose 54 leading from a compressed air source (not shown)to a coupling 56 threaded into member 48 and opening to the interior ofair cylinder 28. The compressed air source may be mounted on the deckI2, or in the cab l6, of the crane I8, as desired. The end of thecylinder adjacent support 58 has an air vent 58 provided therein for apurpose that will be described hereinafter.

The piston 30 consists of a pair of circular face plates 62 and 64 and acup leather 66 therebetween, which cup leather is of greatercross-sectional area than the internal cross-sectional area of aircylinder 28. The cup leather or piston packing 66 serves to provide aseal between the piston 30 and the air cylinder 28. The piston rod 32has a reduced threaded portion 68 and a shoulder 69. The piston plates62 and 64 and the cup leather 66 are mounted on the reduced portion 68.A nut 10 cooperates with the threaded portion 68 to clamp plates 62 and64 and cup leather 66 against shoulder 69 on the piston rod 32.

The piston rod 32 extends from one end of the cylinder 28 and passesthrough a bore "II in cylindrical plug portion 5|. A well 12 forlubricant is also provided in cylindrical plug 5|. A threaded plug 13caps the well 12, providing both access to the well 12 and means forsealing well 12.

The extended end of piston rod 32 has a bifurcated sheave support 14mounted thereon. The pair of sheaves 34 are rotatably mounted on a shaft15 journalled in the arms of bifurcated member 14.

A cylindrical expansible bellows type leather boot 16 extends betweensupport member 58 and bifurcated sheave support 14. The piston rod 32 isenclosed by and extends concentrically within cylindrical boot I6. Theleather boot I6 is secured at its ends by being laced over a collar 11,which is secured to support member 50, and over a collar 18, which issecured to piston rod 32. The bellows type boot 16 serves as a cover toprotect the piston rod 32, and the bore 1|, through which piston rod 32passes, from dust, dirt and the elements.

Adjacent the opposite end of air cylinder 28, another sheave 19 isrotatably mounted on a shaft 80, which shaft 88 is journalled insupporting arms 8|. The supporting arms 8| are secured, as by welding,to support member 48.

The end 38 of first cable 36 is secured to ear 82 on support 48. Thefirst cable then is wound around one of the sheaves 34 and then backover the sheave 19 and then over the second sheave 34 and finally woundaround the first drum 40.

It can be seen that by means of the sheaves a mechanical advantage offour is obtained, in that for each unit of motion of the piston 38within the cylinder 28, four times as much of the first cable 36 eitheris wound upon or winds off first drum 40.

The second drum 44 is of such dimension as compared with the first drum40 that for a unit amount of cable 36 that is wound on or off drum 40,four times as much tagline 24 on drum 44 is, respectively, wound off oron.

By maintaining a uniform fluid pressure in the air cylinder 28,substantially a uniform tension will be maintained in the tagline 24.Furthermore, a mechanical advantage of 16 to 1 is obtained by the sheaveand drum arrangement, as shown in Figure 2. Thus, a unit length ofmotion of the piston 38 results in 16 times as much motion in thetagline 24. This is very desirable because the movements of the cranebucket 22 will be rather large and it is desirable to accommodate thislarge movement by a relatively small movement in the tagline tensiondevice. The tension in the tagline is correspondingly 1 s of the totalforce due to pressure upon the piston 3|).

Primarily, damping of oscillations of the piston 38 within the aircylinder 28 is obtained by the pushing of air into and out of thecylinder 28 on the loaded side, through air hose 54. Further damping ofoscillations of the piston 30 is obtained by increasing the friction ofthe oscillating system. Thus, the piston packing or cup leather 66 ismade a little larger than usual so as to increase thefrictionbetween cupleather 88 and the Wallsof air cylinder 28. Thefluid fric-- tion ofairmovement in and out of cylinder 28 through air'vent 58, as the piston 30is pulled out or allowed to retract, also applies a natural dampingaction upon the system. By varying 7 systems are shown diagrammaticallyin. Figures:

6, 7 and 8. Figure 8 is the simplest and shows a source 84 ofpressurized fluid which is maintained at a. substantially constant.pressure, primarily the pressure desired. within the. air cylin der. Thesource 8.4. is connected to the air cylinder 28 by means of. an air line54. The source 84 is of much greater volume than the volume. of aircylinder 23,. so that when fluid is forced from. air cylinder 28. backto the source 84, there, will be very little increase in the pressureof. the fluid therein, thus maintaining substantially a constantpressure.

In the second system, the source 84 has interposed between it and theair cylinder 28, a pressure reducing valve 86 and a surge chamber 88.The pressure reducing valve 86 permits the source to be maintained at ahigher pressure than the operating pressure in air cylinder 23. Thesurge chamber 88 is provided to receive the fluid that is pushed fromair cylinder 28 when a sudden force is applied to the tagline 2d,causing the piston 38 to force some air from the air cylinder 28. Thesurge chamber 88 absorbs the amount of fluid that is pushed from airchamber 28 without permitting large pressures to be built up against theface of air piston 38. The surge chamber 88 is of much greater volumethan the volume of air cylinder 28.

In the system shown. in Figure 6, a pressure reducing valve. 86 isinterposed between source 84 and the air cylinder 28. A by-pass line 90is provided around pressure reducing valve 86. The by-pass line 90 has acheck valve 92 therein. When the. piston 38 is moved so as to force airout from the air cylinder 28, the check valve 92 permits flow of thisair back. to. the source, and the source effectively acts as. a surgechamber, as. shown in the system diagrammatically illustrated in Figure7. The check valve will operate only if the pressure built up by theforces on piston 30 is greater than the pressure at the source 84.

Thus, it can be seen that my tagline tensioning device overcomes thethree major objec-- tions of other tagline tensioning devices, namely:Its operation is independent of the position of the device or the loadbeing steadied; it is compact and it may be readily mounted on the boomof the crane where it does not occupy valuable space; it has naturalrapid damping characteristics.

While there has been shown and described a particular embodiment of thisinvention, it will be obvious to those skilled in the art that variouschanges and modifications may be made therein without departing from theinvention and, therefore, it is intended in the appended claims to coverall such changes and modifications as fall within the true spirit andscope of the invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

l. A tagline tensioning device in combination with a crane boomhavingalload suspendedfrome the end thereof; and a tagline adaptedz'to.be se--cured to said load; said tagline tensioning dc" vice comprisingacylinder, a piston within said cylinder, means for applying apressurized fluid against the piston, means connecting said piston tosaid tagline, whereby a tension is maintainedin said tagline, and meansfor multiplying the motionv of the piston, whereby a relatively largerange of motion of the tagline is accommodated by a relatively smallrange ofv motion of the piston.

2. A tagline tensioning device in combination with a crane boom having aload suspended from the end thereof, and a tagline adapted to be securedto said load; said tagline tensioning device comprising a cylinder, apiston within said cylinder, means for applying a pressurized fluidagainst the piston, means connecting said piston to said tagline, andmeans for maintaining a substantially constant fluid pressure againstsaid piston, whereby a substantially constant ten.- sion is maintainedin said tagline, said means for maintaining a substantially constantpressure against said piston comprising a source of pressure, a surgechamber, and a pressure control between said source of pressure and saidsurge chamber, the pressure fluid passing from the source through thecontrol and-to the surge chamber and then to said cylinder.

3. A tagline tensioning device in combination with a crane boom having aload suspended from the end thereof, and a tagline adapted to be securedto said load; said tagline tensioning device comprising a cylinder, apiston within said cylinder, means for applying a pressurized fluidagainst the piston, means connecting said p istonto said tagline, andmeans for maintaining a substantially constant gas pressure against saidpiston, whereby a substantially constanttension is maintained in saidtagline, said means for maintaining substantially a constant pressureagainst said piston comprising a source of pressurized gas of muchgreater volume than the volume of said cylinder.

4. A tagline tensioning. device in combination with a crane boom havingaload suspended from the end thereof, and a tagline adapted to be securedto said load; said tagline tensioning device comprising a cylinder, apiston within said. cylinder, means for applying a pressurized fluidagainst the piston, means connecting said piston to said tagline, andmeans for maintaining a substantially constant fluid pressure againstsaid piston, whereby a substantiallyconstant tension is maintained insaid. tagline, said means for maintaining substantially a constantpressure against said piston comprising a source of pressure, a conduitcommunicating fiuid pressure from said source to said cylinder, apressure reducing valve in said conduit, a bypass around with a craneboom having a load suspended from the end thereof, and a tagline adaptedto: be. secured to said load; said tagline tensioning device comprisinga cylinder, a piston within said: cylinder, means for applying apressurized fluid.

against one face of the piston, means for connecting said piston tosaidtagline, means for maintaining substantially a constant fluid pres-'sure against said'piston, whereby a substantially constant tension ismaintained in said tagline;

7: and means for venting to atmosphere the portion of the cylinderbounded by the non-pressurized face of the piston.

6. A tagline tensioning device in combination with a crane boom having aload suspended from the end thereof, and a tagline adapted to be securedto said load; said tagline tensioning device comprising a cylinder, apiston within said cylinder, means for applying a pressurized fluidagainst one face of the piston, means for connecting said piston to saidtagline, means for maintaining substantially a constant fluid pressureagainst said piston, whereby a substantially constant tension ismaintained in said tagline, means for regulating the fluid pressure,means for multiplying motion of the piston, whereby a relatively largerange of motion of the tagline is accommodated by a relatively smallrange of motion of the piston, and means for damping out oscillations ofthe piston including venting to atmosphere the portion of the cylinderbounded by the non-pressurized face of the piston.

7. A tagline tensioning device in combination with the boom of a cranehaving a load suspended from the end thereof, and a tagline adapted tobe secured to said load; said tagline tensioning device comprising acylinder, means for mounting said cylinder upon said crane boom, apiston within said cylinder, means for applying a pressurized gasagainst the piston, means connecting said piston to said tagline, andmeans for maintaining substantially a constant gas pressure against saidpiston, whereby a substantially constant tension is maintained in saidtagline.

8. In combination with the boom of a crane, a tagline tensioning devicecomprising a cylinder, means for mounting said cylinder upon said craneboom, a piston within said cylinder, means for applying a pressurizedfluid against the piston, means connecting said piston to a tagline,means for maintaining substantially a constant fluid pressure againstsaid piston, whereby a substantially constant tension is maintained insaid tagline, said means for connecting the piston to the taglinecomprising a piston rod extending from said piston through one end ofsaid cylinder, the extended end of said piston rod having a plurality ofsheaves mounted thereon, a sheave fixed adjacent the other end of saidcylinder, a first cable fixed at one end thereof and wound around saidsheaves, whereby a mechanical advantage is obtained, the other end ofsaid first cable being wound around a first drum, said first drum and asecond drum being fixed to a shaft adapted to rotate, said shaft beingrotatably mounted upon said crane boom, said second drum having one endof the tagline wound thereupon.

9. A tagline tensioning device in combination with a crane boom having aload suspended from theend thereof, and a tagline adapted to be securedto said load; said tagline tensioning device comprising a cylindersealed at both ends, a piston within said cylinder, means for applying apressurized gas against one side of said piston, means connecting saidpiston to said tagline, and means for venting the portion of thecylinder bounded by the non-pressurized side of the piston, whereby thefluid friction of air movement in and out of the cylinder through saidventing means applies a damping action to the piston.

10. A tagline tensioning device in combination with a crane boom havinga load suspended from the end thereof, and a tagline adapted to besecured to said load; said tagline tensioning device comprising acylinder sealed at both ends, a piston within said cylinder, means forapplying a pressurized gas against one side of said piston, meansincluding a piston rod extendin through one end of said cylinder foroperatively connecting said piston to said tagline, means for dampingout oscillations of the piston, and a cylindrical expansible bootcoaxially surrounding the piston rod, said boot being connected at oneend to the cylinder and at the other end to the extended end of thepiston rod.

11. A tagline tensioning device in combination with a crane boom havinga load suspended from the end thereof, and a tagline adapted to besecured to said load; said tagline tensioning device comprising acylinder sealed at both ends, a piston within said cylinder, means forapplying a pressurized fluid against one side of said piston, meansincluding a piston rod extending through one end of said cylinder foroperatively connecting said piston to said tagline, means formaintaining a substantially constant fluid pressure against said piston,whereby a substantially constant tension is maintained in said tagline,means for damping out oscillations of the piston, and a cylindricalexpansible boot coaxially surrounding the piston rod, said boot beingconnected at one end to the cylinder and at the other end to theextended end of the piston rod.

12. A tagline tensioning device in combination with a crane boom havinga load suspending from the end thereof, and a tagline adapted to besecured to said load; said tagline tensioning device comprising acylinder, a piston within said cylinder, means for applying apressurized gas against the piston, means operatively connecting thepiston to said tagline, said means for connecting the piston to thetagline comprising a piston rod extending from said piston through oneend of said cylinder, the extended end of said piston rod having aplurality of sheaves mounted thereon, a sheave fixed adjacent the otherend of said cylinder, a first cable fixed at one end thereof and woundaround said sheaves, whereby a mechanical advantage is obtained, theother end of said first cable being wound around a first drum, saidfirst drum and a second drum being fixed relative to each other andadapted to be rotated together, and said second drum having one end ofthe tagline wound thereupon.

PHILO A. ORTON, SR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 470,936 Jones Mar. 15, 1892605,044 Hall May 31, 1898 612,722 Hall Oct. 18, 1898 709,974 Ennes Sept.30, 1902 2,010,006 Bosch Aug. 6, 1935 2,194,933 Fullerton Mar. 26, 19402,283,784 Billings May 19, 1942 2,303,002 Ruddock Nov. 24, 19422,367,912 Westfall Jan. 23, 1945 2,411,498 Billings Nov. 26, 19462,532,828 Westfall Dec. 5, 1950

